There are certain places you'd expect the developers of a well-known military shooter to look for inspiration. What you perhaps don't expect is for the team behind the latest Call of Duty title to count among their influences an elegiac cooperative indie game about the meaning of life. You don't expect them to play Journey. But according to Michael Condrey, co-founder of Sledgehammer Games, the San Francisco studio behind Call of Duty: WWII, that's exactly what they did. The next instalment of Activision's military behemoth takes the action back to the second world war, returning to the origins of the series.

There's one thing you're going to hear over and over in relation to Call of Duty: WWII's multiplayer experience: "Boots on the ground." The four-word catchphrase refers to the way WWII strips out the modern contrivances of more recent games -- such as booster packs and exoskeletons -- in favor of more traditional close combat. It amounts to a simplification: everyone will have an easier time getting a handle on Call of Duty multiplayer in WWII. SEE ALSO: The painstaking process behind making strategy guides, from the guy who's spent his life doing it Sledgehammer Games focused primarily on the game's story mode in its April 26 reveal, but we did pick up a few facts about how PvP action will factor in. Headquarters is one of the most intriguing ideas in the new multiplayer. It sounds like Sledgehammer will introduce a new online social space, something Call of Duty hasn't ever seen before.